Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
1 rating

Sunday - August 01, 2010

From: Las Vegas, NV
Region: Rocky Mountain
Topic: Diseases and Disorders, Watering
Title: Arizona ash tree with brown leaf tips in Las Vegas NV
Answered by: Barbara Medford

QUESTION:

We've had an Arizona Ash Tree in our yard for over 7 years it was doing fine until last summer, the tree seems to be struggling with the heat, its leaves look like they are burning up and turning brown at the very top, is there anything we can do to help it?

ANSWER:

According to this USDA Plant Profile Map, Fraxinus velutina (velvet ash) grows natively in your area of Clark County, USDA Plant Hardiness Zones 8b to 9b, so your problem should not be with soil or climate. Unless you are having a most unusually hot summer, hotter than last year, you need to ask yourself what in the environment has changed to cause that tree to have leaf tips browning?

We will do a little research into the Arizona Ash and see if we can find what might be causing a symptom you have not seen before. None of the sites we looked at mentioned any disease that caused that sort of leaf browning, but there were several mentions that this tree depended on an underground water source or was "riparian" meaning it likes river bottoms or other locales where there is a constant supply of water for its roots. We are wondering if perhaps you are having an unusually dry year in Nevada and that underground water has diminished. One source recommended deep irrigations of the tree two or three times a month during extremely dry spells. This would mean getting a hose down in the dirt around the roots, turning it on to a slow dribble and letting it run until water appears on the soil surface. The leaves browning at the top of the tree would seem to be indicative of this, as all the moisture and nutrition for the tree comes up from the roots. The leaves at the very top, the end of the line, as it were, would be most susceptible to moisture deprivation. 

Another possibility, although more remote, is that of ash borers. See this article from Colorado State University Extension on Ash Borers.  This article points out that borers are more apt to attack trees weakened from drought or other reasons. However, first see if there are any signs of the beetles before you try pesticide. For more information on the possibility of ash borers in your vicinity, contact the University of Nevada Cooperative Extension Office for Clark County. 

 

More Watering Questions

Plants for science fair project using greywater
November 17, 2013 - What kind of plants should we use for our science fair project.We are doing our project on how greywater affects plant growth. We saw your answer on how it affects it but we don't know what type of ...
view the full question and answer

New growth on live oaks in Houston
September 27, 2011 - My 2 10yr. old live oaks are putting out new growth (branches?) although, here in Houston, TX we are having such a drought. For the last 3 months, I have conscientiously watered my entire yard via ...
view the full question and answer

Non-native lambs ears wilting in heat from Fredericksburg TX
October 19, 2011 - 3 days ago I had professional landscaping done in an area with plants that tolerate heat & sun well. We planted 7 healthy, large lambs ear & mulched. Everything planted is doing well except the lambs ...
view the full question and answer

Recovery of water-stressed Agarita
August 11, 2014 - Hello! I planted a small agarita at the end of May and then left town for six weeks. During that time it was supposed to receive weekly deep irrigations to help it establish, but it seems that som...
view the full question and answer

Mites in soil of house plants
June 25, 2008 - Hi there! I recently noticed tiny silver mites in the soil of my plants that I only notice after watering. These plants are indoors in on a window ledge (a dwarf palm, aloe plant and Hawaiian Scheffle...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.